One method of producing conductor rails is described in French Patent Specification No. 2 286 680 and comprises bending the steel facing layer into contact with the main body and then effecting a crimping operation to key the facing strip into interlocking engagement with the main body.
Another method of producing conductor rails is described in Applicant's U.S. Pat. No. 5,047,595 and includes forming the facing layer as two or more portions which are welded together in contact with the main body in such manner as to obtain a mechanical interlocking engagement of the facing layer with the main body.
The steel from which the facing layer has been formed has been stainless steel and, traditionally, the chromium content of the stainless steel has been of the order of 18% by weight since this percentage chromium has been considered necessary to obtain the optimum characteristics for the facing layer. The use of a stainless steel of this composition is mentioned in, for example, British Patent Specification No. 1 415 904.
It is an object of the present invention to provide a conductor rail comprising a main body of aluminium and a steel facing layer in which the composition of the steel is such as to provide improved characteristics as compared to the use of a steel having an 18% by weight chromium content.
In addition, it is an object of the present invention to provide a conductor rail as discussed above which has cost-saving advantages as compared with a conductor rail which includes a facing layer formed from a stainless steel having an 18% by weight chromium content.